Prevalence of antibodies against measles, mumps, and rubella before and after vaccination of school-age children with three different triple combined viral vaccines, Rio Grande do Sul, Brazil, 1996

OBJECTIVE

We evaluated the seroprevalence for measles, mumps, and rubella in school-age children (6-12 years old) before and after the administration of three triple combined viral vaccines.

METHODS

In two municipal schools of Rio Grande do Sul, Brazil, 692 blood samples were collected before vaccination and 636 samples 21 to 30 days after vaccination during 1996. IgG antibody seropositivity was investigated by enzyme-linked immunosorbent assay (measles and mumps with Enzygnost [Behring, Marburg, Germany]; rubella with Rubenostika [Organon Teknica, Boxtel, the Netherlands]). The vaccines compared were: A: E-Zagreb, L-Zagreb, and Wistar RA 27/3 (Tresivac); B: Moraten, J-Lynn, and Wistar RA 27/3 (M-M-R II); and C: Schwarz, Urabe AM-9, and Wistar RA 27/3 (Trimovax).

RESULTS

Before vaccination, 79.2% [95% confidence interval (CI)=76.0%-82.2%] of the samples were positive for measles, 69.4% (95% CI=65.8%-72.8%) for mumps, and 55.4% (95% CI=51.6%-59.2%) for rubella. After vaccination with the A, B, and C vaccines, seropositivity was 100.0%, 99.5%, and 100.0%, respectively for measles; 99.5%, 94.5%, and 92.0% for mumps; and 92.6%, 91.3%, and 88.6% for rubella.

CONCLUSIONS

About one-fifth (20.8%) of the schoolchildren who could have been vaccinated against measles at age 9 months had levels of antibodies insufficient for protection. In the sample of schoolchildren without previous vaccination against mumps and rubella, high proportions of susceptible levels were found. All vaccines were immunogenic, but vaccine A yielded a seroconversion rate of 99.5% for the mumps component, which was significantly higher than the other two vaccines (P<0.01).

Neutrophil alkaline phosphatase activity in respiratory viral infection

Neutrophil alkaline phosphatase (NAP) is used as a diagnostic marker in several hematological disorders. In regard to the role of NAP in infectious diseases, previous investigators have presented the hypothesis that NAP activity is useful to distinguish viral infections from bacterial infections. Because the numbers of patients enrolled in previous studies of viral infections were limited, we intended to evaluate the hypothesis by measuring NAP activity in a large number of pediatric patients with respiratory viral infections. A cytochemical analysis of NAP was performed in 160 patients with various types of respiratory infections. In patients with adenovirus or respiratory syncytial (RS) virus infection, NAP activity was significantly higher than the control value newly established at our department, while in patients with Epstein-Barr virus, measles, or influenza infection, it was comparable to the control value. On an individual basis, NAP scores (determined from NAP cytochemical activity) in 22 of 26 patients (84.6%) with adenovirus infection, and 31 of 42 patients (73.8%) with RS virus infection were found to exceed the 95% confidence upper limit of the control group. In conclusion, NAP activity is quite varied among different respiratory viral infections. When NAP activity is high in respiratory infections, adenovirus or RS virus infection, as well as bacterial infections, should be taken into consideration.

Seroprevalence of measles, mumps, rubella and varicella among staff of a hospital in Riyadh, Saudi Arabia

This study aimed at screening immune status of Health Care Workers (HCWs) against measles, mumps, rubella, and varicella, and assessing the reliability of the history of previous illness due to these infections or vaccination against them as an indicator of the immune status, as checked by laboratory tests. Demographic data, history of previous illnesses and previous vaccinations were collected using a self-administered questionnaire. Also, serologic screening was done for these infections. Antibodies tested using ELISA. Among tested hospital staff, 71.8%, 60.3%, 47.9% and 68.4% reported history of infection or vaccination against measles, mumps, rubella and varicella respectively, while laboratory results proved that 4.5%, 10.8%, 12.9% and 11.3% were susceptible respectively. Susceptibility was most frequent among housekeeping staff against measles and varicella, while administrative staff were the most susceptibles to mumps, and nurses were the most susceptibles to rubella. Sensitivity of past history of illness as an indicator of the immune status, was found to be (85%, 83%, 66%, 86%); Specificity was (81%, 81%, 89%, 87%); Positive Predictive value (PV) was (99%, 98%, 98%, 98%) and Negative PV was (16%, 29%, 22%, 39%) for measles, mumps, rubella and varicella respectively. Screening for measles, mumps, rubella and varicella among hospital staff is mandatory to detect those who are susceptible for infections and should be vaccinated, and so preventing transmission of these infections to their colleagues or patients.

Distinguishing between primary measles infection and vaccine failure reinfection by IgG avidity assay

In this study in the Islamic Republic of Iran 365 measles cases were evaluated to distinguish between primary infection with measles and reinfection due to secondary vaccine failure. All cases previously confirmed by detection of specific IgM were tested for IgG avidity. A secondary immune response was seen in 18.4% of patients. All unvaccinated patients (16.7%) showed a primary immune response. Of 244 patients with documented vaccination, 75.8% showed a primary immune response and 24.2% showed a secondary immune response, thereby indicating a secondary vaccine failure. Almost all measles reinfections (99%) were seen in patients >10 years old, indicating that vaccination for 10-year-old children is recommended.

Measles seroepidemiology among adolescents and young adults: response to revaccination

We evaluated the seroprevalence of measles antibody and response to measles reimmunization in 590 previously vaccinated adolescents and young adults; 263 were seronegative. To differentiate between primary and secondary vaccine failure, anti-measles IgM and IgG titres were assessed again 2-4 weeks after revaccination in 144 (105 seronegative, 39 seropositive) individuals: 75 seronegative participants responded to revaccination anamnestically (P < 0.001) and developed immunity, 11 also showed IgM response (probably primary vaccine failure); 38 seropositive participants remained seroprotected without significant increase in antibody titre (P = 0.577). Primary vaccine failure was 4.7%; secondary vaccine failure was 27.1%. After revaccination, 87.3% were seroprotected.

High pathogenicity of wild-type measles virus infection in CD150 (SLAM) transgenic mice

Measles virus (MV) infection causes an acute childhood disease, associated in certain cases with infection of the central nervous system and development of a severe neurological disease. We have generated transgenic mice ubiquitously expressing the human protein SLAM (signaling lymphocytic activation molecule), or CD150, recently identified as an MV receptor. In contrast to all other MV receptor transgenic models described so far, in these mice infection with wild-type MV strains is highly pathogenic. Intranasal infection of SLAM transgenic suckling mice leads to MV spread to different organs and the development of an acute neurological syndrome, characterized by lethargy, seizures, ataxia, weight loss, and death within 3 weeks. In addition, in this model, vaccine and wild-type MV strains can be distinguished by virulence. Furthermore, intracranial MV infection of adult transgenic mice generates a subclinical infection associated with a high titer of MV-specific antibodies in the serum. Finally, to analyze new antimeasles therapeutic approaches, we created a recombinant soluble form of SLAM and demonstrated its important antiviral activity both in vitro and in vivo. Taken together, our results show the high susceptibility of SLAM transgenic mice to MV-induced neurological disease and open new perspectives for the analysis of the implication of SLAM in the neuropathogenicity of other morbilliviruses, which also use this molecule as a receptor. Moreover, this transgenic model, in allowing a simple readout of the efficacy of an antiviral treatment, provides unique experimental means to test novel anti-MV preventive and therapeutic strategies.

Seroprevalence of measles, rubella, and mumps antibodies in Catalonia, Spain: results of a cross-sectional study

Determination of antibody levels against vaccine-preventable diseases is of great value to assess immunization programmes. The objective of this study was to determine the prevalence of measles, rubella, and mumps antibodies in representative samples of the child and adult population of Catalonia and compare the findings to those obtained in 1996. A representative sample of the child and adult (>or=15 years) population of Catalonia was studied. Enzyme-linked immunosorbent assay techniques were used to determine the presence of antibodies. Equivocal results for antibodies against measles and rubella were tested using an immunofluorescence technique. To compare proportions, the chi-square test and the Fisher's exact test were used. Statistical significance was set at 0.05. Adjusted odds ratios were calculated using multiple logistic regression analysis. Samples from 2,619 people were analyzed. The global prevalence of antibodies was 98.3% for measles, 91.1% for mumps, and 98.1% for rubella. The prevalence of rubella antibodies was higher in women than in men (98.8 vs. 97.2%, respectively). Compared with the results obtained in the 1996 seroprevalence study, only the prevalence of rubella antibodies showed a statistically significant increase in men (97.2 vs. 94.6%; p=0.002) and, in particular, in women (98.8 vs. 95.3%; p<0.001). The low prevalence of susceptible subjects has already led to the elimination of indigenous measles in Catalonia and should allow the elimination of indigenous rubella by 2005. The level of antibodies necessary to interrupt the transmission of mumps has still not been reached in all age groups.

The role of serum KL-6 measurement in common pediatric respiratory infections

KL-6 is a useful marker for interstitial pneumonia of various origins. However, the role of KL-6 in common pediatric respiratory infections is largely unknown. In order to determine whether the KL-6 level is elevated during respiratory infection, and whether KL-6 is a useful biomarker for the disease activity, we evaluated serum KL-6 levels in 132 children with various respiratory infections. KL-6 levels were significantly higher in patients with measles, influenza, or respiratory syncytial virus infection than in the control subjects. On the other hand, KL-6 levels in patients with bacterial infections such as mycoplasma, chlamydia, or pertussis were comparable to the control values. In patients with viral infections, high KL-6 levels, as defined by the mean plus 2 standard deviations of the control group, significantly correlated with low SpO(2) or days of O(2) administration, but did not correlate with C-reactive protein or white blood cell counts. These results indicate that measurement of serum KL-6 levels is helpful for the management of common pediatric respiratory infections.

Waning antibodies in measles and rubella vaccinees—a longitudinal study

The evolution of measles- and rubella-specific serum IgG was followed in a longitudinal study in 224 young adolescent vaccinees, with or without boost vaccination before or during the 6.8-year observation period. Antibody titres were monitored by enzyme immuno assay (Enzygnost, Dade-Behring). After revaccination (second dose) rubella seropositivity rate increased from 92.1 to 100%, whereas measles seroprevalence (about 90%) did not significantly change between the paired sera. Significantly higher IgG (> three-fold) in the second serum of 5.2% (measles) and 7.8% (rubella) of participants with low antibodies (measles: < 1500 mIU; rubella < 40 IU) in first serum, suggest a secondary immune response (SIR) during the study period, only partially explained by revaccination. Excluding individuals with SIR, minimal annual antibody decay rates of -2.9% (confidence interval, CI: -0.7 to -4.8%) for rubella and -1.6% (CI: -0.1 to -3%) for measles were determined in participants with single dose vaccination. Thus, two-dose vaccination was adequate to protect women from rubella infection at least during childbearing age. Similarly only few individuals may become seronegative for measles again after successful vaccination due to minimal waning of low antibody levels (< 1500 mIU). However, as a result of a more rapid decay of high-titre (> 1500 mIU) antibodies (-2.4%/year), many vaccinees may eventually become susceptible to vaccine-modified measles (VMM) and consequently complicate measles control strategies.

Detection of serum neopterin for early assessment of dengue virus infection

Objective

Neopterin is generated and released in increased amounts by macrophages upon activation by interferon-γ during Th1-type immune response. The potential usefulness of neopterin in early prognostic information of dengue virus infection was investigated.

Methods

Neopterin concentrations were determined in serum samples from 110 dengue fever (DF) patients. The neopterin levels were compared with those in 50 measles and 40 influenza patients; 155 healthy blood donors served as controls.

Results

In acute sera of DF patients mean neopterin concentration was 48.2 nmol/L, which was higher than that in patients with measles (mean: 36.3 nmol/L) and influenza (18.8 nmol/L) and in healthy controls (6.7 nmol/L; P < 0.001). In the patients with confirmed DF, an early neopterin elevation was detected already at the first day after the onset of symptoms and rose to a maximum level of 54.3 nmol/L 4 days after the onset. Higher increase of neopterin level in DF patients was associated with longer duration of fever and thus predicted the clinical course of the disease.

Conclusions

Neopterin concentrations were found significantly higher in DF patients compared with healthy controls and also with other viral infections (P < 0.001) and may allow early assessment of the severity of DF.

Absence of detectable measles virus genome sequence in blood of autistic children who have had their MMR vaccination during the routine childhood immunization schedule of UK

Leukocyte preparations from children with documented evidence of MMR vaccination and confirmed diagnosis of autism were examined by several assays designed to target multiple regions of the measles virus genome sequence. No sample was found positive by any method. The assays applied were highly sensitive, specific and robust in nature, and were based on the amplification of measles virus RNA transcripts by real-time quantitative RT-PCR (QRT-PCR) as well as by conventional RT-PCR-nested PCR. The assays applied were potentially able to detect measles virus RNA down to single figure copy numbers per reaction. The amount of total nucleic acid extract of leukocytes subjected to various measles virus-specific investigations was several fold higher than minimally required of a sample where measles virus persistence is well documented. This study failed to substantiate reports of the persistence of measles virus in autistic children with development regression.

Epidemiological study of measles in Ghazvin, Islamic Republic of Iran, April 1997-April 2003

We studied measles incidence and morbidity in Ghazvin district by retrospective review of cases registered at the central health office and admitted to two hospital in Ghazvin city during April 1997-April 2003. There were 824 clinically confirmed cases of measles over the 6-year period giving a mean annual incidence of 18.67 per 100 000 population, higher than for the country generally. There were no deaths from measles. Of the 824 cases, 591 (71.1%) had serum specimens for serological analysis and 199 (24.3%) were confirmed serologically. Of the serologically confirmed cases, the greatest proportion (44.2%) were over 20 years (median age was 17.5 years), 54.5% had been in contact with a measles case and 21.6% cases had received 2 doses of vaccine. We studied 33 serologically confirmed hospitalized cases. Common complications were vomiting (45.5%), diarrhoea (42.4%) and pneumonia (21.2%). The mean duration of hospitalization was 3.8 days.

Rubella and measles seroprevalence among women of childbearing age, Argentina, 2002

To assess rubella and measles susceptibility among women of childbearing age we conducted a cross-sectional seroprevalence study in four cities and one rural area in Argentina. A convenience sample of women aged 15-49 years seeking care in public health-care institutions was selected (n=2804). Serum specimens were tested for rubella and measles IgG antibody titres. The overall susceptibility to rubella and measles was 8.8 and 12.5% respectively. Seroprevalence differences were found for both rubella (P<0.001) and measles (P=0.002) across sites. Rubella seroprevalence was higher in women aged >or=40 years than in younger women (P=0.04). Measles seroprevalence tended to increase with age (P<0.001). Approximately 15% of women aged 15-29 years were not immune to measles. No risk factors were associated with rubella seronegativity; however, age (P<0.001) and having less than four pregnancies (P<0.001) were factors associated with measles seronegativity. Our findings support the introduction of supplemental immunization activities targeting adolescents and young adults to prevent congenital rubella syndrome and measles outbreaks over time.

Measles seroprevalence of an adolescent population vaccinated with a single dose of measles vaccine before their first birthday

This study determined the age-specific measles seroprevalence of an adolescent population in Ankara vaccinated with a single dose of measles vaccine before their first birthday. The study sample included 440 adolescents (227 female, 213 male) aged 9-16 years admitted to the Adolescent Outpatient Clinic of Hacettepe University Faculty of Medicine. For each participant, a questionnaire was completed and measles specific IgG antibodies screened quantitatively by the enzyme linked immunosorbent assay. Of the 440 subjects screened for measles antibodies, 114 (25.9 %) were seronegative. Measles seronegativity according to sex and age groups were, 32.6, 24.7, 13.3% in females and 29.5, 30.1, 6.3% in males in the age groups of 9-11, 12-14, 15-16 years, respectively. In countries where the two dose vaccination schedule against measles has not been incorporated to the national immunization program, the adolescent health maintenance visit at age 11-12 years should serve as an opportunity to evaluate vaccination status and administer MMR vaccine to all adolescents who have not received two doses at the recommended ages.

Immunoglobulin G subclass profile of antimeasles response in vaccinated children and in adults with measles history

The aim of this study was to investigate measles-specific immunoglobulin G (IgG) subclass profile in vaccinated children and in adults with natural infection. Serum samples were collected before and 30 days after vaccination. The sera from 51 late convalescent adults and seven adults with natural measles infection at the 12th day after onset of rash have been also investigated. Measles IgG antibodies and specific IgG subclasses were tested by enzyme-linked immunosorbent techniques. In children younger than 3 years, the predominant subclass was IgG3, which contributed, on average, 63.3% of the total IgG response. The contributions of specific IgG1 and IgG4 to the total IgG antimeasles response were lower (19.9% and 16.8%, respectively), whereas IgG2 was not found. In contrast, in the group of children older than 4 years, just IgG2 was a predominant subclass; it contributed 42.6% of the total IgG response. Other subclasses were also present but the contribution was much lower. In adult volunteers with measles history, IgG2 was a predominant subclass of total IgG. Thus, in early convalescence IgG2 contributed 62% of the total IgG response, whereas in late convalescence the contribution was lower (41.4%). There were no visible differences in IgG subclass composition between subjects with natural infection and vaccinated children except those below 3 years of age. The humoral immune response of such subjects is immature and the IgG2 subclass of virus-specific antibodies has not been revealed in the sera.

Identification of measles virus genotypes from recent outbreaks in countries from the Eastern Mediterranean Region

BACKGROUND

Molecular characterization of measles viruses (MV) helps to identify transmission pathways of the virus and to document persistence or interruption of endemic virus circulation. In the Eastern Mediterranean Region, measles genotypes from only few countries have been documented.

OBJECTIVES

This study reports the genetic characteristics of virus strains from recent measles outbreaks in Tunisia, Libya, Syria and Iran in 2002-2003.

STUDY DESIGN

Virus sequences in the nucleoprotein gene were obtained by PCR amplification of virus isolates or serum samples. The sequences were compared to the reference ones for genotype identification and to other published sequences within the same genotype.

RESULTS AND CONCLUSIONS

The Tunisian and Libyan epidemic strains belonged to genotype B3, they were closely related to each other and to isolates from Western Africa. The Syrian and Iranian viruses belonged to genotype D4, and differed from each other and from the other published sequences within this genotype. Our results provide valuable baseline and new tools for improved virological measles surveillance in the future, at country, regional and global levels.

Circulating leukocyte and cytokine responses to measles and poliovirus vaccination in children after ultraviolet radiation exposures

Suberythemal ultraviolet radiation (UVR) exposures of children are used routinely in Russia to prevent rickets and to strengthen general health. The aim of the present study was to re-evaluate the effects of such a regime on immune responses as UVR is now recognised to suppress cell-mediated immunity in many animal models. Seventeen infants were immunised with attenuated measles and recall polio vaccines of whom 10 had been given a course of prophylactic UV exposures before the vaccinations. All the infants in the study developed an acute infectious conjunctivitis one week prior to the vaccinations and were convalescent at the time of the vaccination. They were bled on the day of the vaccinations and at several times thereafter to assess leukocyte percentages and plasma cytokine levels. On the day of the vaccinations, an active immune response was apparent. The UV-exposed children differed from the unexposed children by having a smaller percentage of natural killer cells and a higher percentage of CD25-positive cells. In the days following the vaccinations, the UV-exposed infants had a lowered percentage of total lymphocytes with increased percentages of monocytes, eosinophils, neutrophils and HLA-DR-positive cells as well as higher concentrations of plasma IL-1beta and IL-10 compared with the unexposed infants. There were no local or systemic clinical reactions to the vaccines in the UV-group while a moderate rise in temperature of three children in the unexposed group occurred. Thus the UV irradiations modulated leukocyte percentages and plasma cytokine levels following the vaccinations, perhaps through the activation of a T helper 2-like response.

[Structural and ultrastructural changes in thrombocytes of patients with measles before admittance to the hospital and after discharge]

Thrombocytes have been studied at the admittance to the hospital of patients with measles and after their discharge using light and electron microscopy. Response of thrombocytes to antigen penetrated into the organism has been shown, however, it appears to be absolutely different before and after the treatment. Structural indices of thrombocytes were studied in their functional aspect. Obtained parameters of thrombocytes at the admittance of patients to the hospital indicate that giant forms of thrombocytes are prevailed and "biological net" is absent, while before discharge of patients the number of mature thrombocytes increases, and amount of giant forms decrease to the minimum. There appears a "biological net", playing an important role in the adsorption of the antigen. Proceeding from this, functional possibilities of thrombocytes, first of all, are directed to defense of the macroorganism from viral antigen. In its turn, measles virus having an influence on the thrombocytes can induce relieve of granules from their body, which also can seem to be the defensive reaction against the antigen.

Development of a semi-quantitative real-time RT-PCR for the detection of measles virus

Real-time detection of polymerase chain reactions allows convenient detection and quantification of virus-derived nucleic acids in clinical specimens. We have developed a real-time RT-PCR assay for the detection of measles virus (MV) genomic RNA, and compared it to a well-established conventional RT-PCR assay. Based on a serial dilution of the live-attenuated MV Edmonston Zagreb vaccine, the detection limits were approximately 0.1 and 0.02 cell culture infectious dose 50% units (CCID50) per test for the conventional and TaqMan RT-PCR assays, respectively. Furthermore, tissue materials spiked with known quantities of MV were equally well detected in both assays. The TaqMan assay was linear within a range of 10(4.4) to 10(-0.6)CCID50/ml, with an intra-assay variability lower than 3% and an inter-assay variability ranging from 1.5% at 10(4.4)CCID50/ml to 8.7% at 10(-0.6)CCID50/ml. The TaqMan assay could detect representative wild-type viruses from the currently active MV clades, and could detect MV genome in clinical specimens obtained from measles patients. Finally, quantification of MV RNA in peripheral blood mononuclear cells or broncho-alveolar lavage cells from cynomolgus macaques collected at different time points after experimental infection showed a good correlation with virus isolation data. In conclusion, the TaqMan assay developed is specific, sensitive, rapid and reproducible, and can be of use for diagnostic purposes or for studies on the pathogenesis of measles.

Subacute sclerosing panencephalitis in the differential diagnosis of encephalitis

The authors describe five cases of subacute sclerosing panencephalitis (SSPE) identified through the California Encephalitis Project that emphasize the importance of considering SSPE in the differential diagnosis of encephalitis, particularly among pediatric patients. SSPE was not suspected in the differential diagnosis of three of the cases until results of measles testing were known. The diagnosis of SSPE is often not considered by clinicians because of its rarity in the United States and the nonspecific clinical manifestations at onset.

Prevalence of measles antibody in children of different ages in Shiraz, Islamic Republic of Iran

An outbreak of measles due to secondary vaccine failure prompted this investigation into the prevalence of measles antibody in children. We studied 608 children in 7 different age groups: 6, 9, 14 and 18 months and 6, 10 and 15 years. Children in the 2 youngest groups received no vaccination; the rest were vaccinated at 9 months and 15 months. The 15-year-old age group received an additional vaccination. Transplacental measles antibody (Ab) decreased from 10.0% at 6 months to 0% at 9 months. Measles Ab was positive in 52.9% (14 months), 89.4% (18 months), 60.8% 96 years), 45.0% (10 years) and 96.8% (15 years). To increase Ab levels, a booster vaccination is recommended, administered either with the second DPT booster or at pre-high school age.

Metabolic effects of acute measles in chronically malnourished Nigerian children

We hypothesized that acute measles infection imposes severe metabolic demands on malnourished children. Nigerian rural communities, characterized by severe poverty and extensive malnutrition, served as site for this study. Sixty-five children (mean [+/-SD] age 2.67 +/- 1.96 years) with measles and a randomly selected equal number of children (age 2.83 +/- 1.23 years) from the same communities but measles-free were studied. Both groups were serologically negative for human immunodeficiency virus. The percentages of nonmeasles group who were underweight and wasted as exemplified by weight for age (WAZ) and weight for height (WHZ) scores less than -2.0 SD were 43% and 23%, respectively. Comparative values for the measles group (66% and 54% respectively) were significantly (P < 0.01 or 0.001) different. Compared to the controls, measles-infected children had significantly (P < 0.001) higher plasma cortisol level, marked hyporetinemia (plasma retinol 0.62 +/- 0.24 micromol/L) and prominent reduction (P < 0.002) in the sum of serum essential amino acids. Measles promoted a TH(1) to TH(2) cytokine shift, with severe depletion of plasma interleukin (IL)-12, a key cytokine in the development of cell mediated immunity. IL-6, a key stimulator of hepatic acute phase protein response, was prominently (P < 0.002) increased in plasma in measles-infected children. Glucocorticoids exert effects on cytokine expression, as well as on cytokine receptor expression and cytokine-regulated biological responses. They enhance synergistically, the effects of IL-1 and IL-6 type cytokines on many acute phase proteins. Because of the prominent increase in circulating level of cortisol in acute measles, glucocorticoid treatment for associated sepsis may pose serious problems. Additionally, glucocorticoids antagonize several effects of retinoids at cellular and transcriptional levels, thus suggesting that hypercortisolemia may increase the requirement for retinoids.

Immunity to measles in the Croatian population

In the frame of measles elimination activities, sera from 1205 Croatian citizens from all parts of the country and of all ages were tested, using Gull Laboratories ELISA, for measles IgG. Equivocal results were found in 50 subjects. Of the remaining 1155 participants, 118 or 10.2% were negative and 1037 or 89.8% positive. The proportion of seronegatives ranged from zero (age groups 41-50, 51 and more) up to 21.4% (1 year of age). As for their distribution into age groups suggested by the European Regional Office of WHO, there were 12.7, 8.9, 9.5 and 8.8% negatives in age groups 1-4, 5-9, 10-14 and 15 + years, respectively. According to these results, only the first two age groups meet WHO criteria, indicating that vaccination coverage higher than the reported 90-94% should be attained if one is to expect measles elimination.